The present invention relates to a headrest for use on wheelchairs and the like to support the heads of individuals with hypertonic extension patterns and, in particular, to a headrest providing improved position relief during extension episodes.
Hypertonia is an abnormal increase in muscle tension that can be expressed in uncontrollable muscle spasms and that may be associated with disabilities such as cerebral palsy or the like. Hypertonicity of the neck muscles can result in neck hyper-extension and injury to an individual if their head is not properly supported during the extension episodes.
A standard headrest, for example, incorporated into a wheelchair or other similar device, can be inadequate for dissipating the force of hypertonic extension because of its relatively unyielding nature. For this reason it is known to mount headrests on the shaft of a gas spring whose body is affixed to the wheelchair. The gas spring allows position relief permitting the head to move backward in the direction of the dominant muscles while absorbing and dissipating the energy of the extension.